The three go together. The following is an email I sent to a member of a listserv I am on. (An 80 something fervent atheist with a PhD in astronomy from Harvard):
If time is infinite on both ends, then we have infinite rolls of the dice of probability. That means, however infinitesimally small the probabilities that brought "you" into existence, with enough rolls of dice, "you" will come into existence again, and again and again forever. And if time is infinite in reverse, "now" isn't the only time "you" existed.
Accordingly, "you" have always existed and always will.